QUESTION
As a standard rule, when given multiple inspection points taken via CMM or other method, how do you report the data to the customer? Do you report the worst case, the average or the range of data?
ie, if a profile of unilateral distribution is .006, and 9 inspection points are taken along the surface with results that range from .0016 to .0031 from nominal; do you report the maximum profile of .0062, the average profile of .0047 (averaging all 9 profile points), or the range of .0032 to .0062?
I can’t seem to find a true standard, and I’ve always reported the worst case, but have recently found that others within my company report the average value, and some report the range of min to max. The way the profile is reported actually has an effect on whether or not the surface is reported as out of tolerance, so I want to make sure I get this right.
REPLIES
HGMorgan
Worst case or range is acceptable.
Range is better in most cases, stated as:
(Design Tol,I.E.; Profile sysmbol, Tol, Datums {Note Unilateral Outside/Inside}) 9 ea PT’s on profile ck from +.0032 to +.0062.
Average is not acceptable, that would show your example as being with/in tolerance(.0047), when it is not(.0062).
SOURCE
https://www.eng-tips.com/viewthread.cfm?qid=248758
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